MSK 1 - Skeletal System Flashcards
1
Q
What are the main functions of the skeletal system?
A
Support structure and movement, protect internal organs, produce blood cells, store triglycerides, store and release minerals
2
Q
Give examples of cavities protected by the skeletal system
A
Cranial, thoracic, abdominal, pelvic, gastrointestinal tract
3
Q
What types of blood cells are produced in bone and where / from what are they made?
A
Red and white blood cells; within red bone marrow; from hematopoietic stem cells
4
Q
What triglycerides are stored in bone and where exactly are they stored?
A
Adipocytes (fat cells); yellow bone marrow within the medullary cavity of long bones
5
Q
What minerals are stored in bone and where exactly are they stored?
A
Calcium and phosphate; within the extracellular matrix of bone
6
Q
What are the two main divisions of the skeleton
A
Axial and appendicular
7
Q
What is the function of the axial skeleton
A
Encloses and protects body cavities
8
Q
Where / what is the axial skeleton
A
Head and trunk
9
Q
What is the function of the appendicular skeleton
A
Supports movement and locomotion
10
Q
Where / what is the appendicular skeleton
A
Upper and lower limbs
11
Q
What are the three structural parts of bone
A
Spongey, compact, medullary cavity
12
Q
What is spongey bone
A
Internal porous layer of bone
13
Q
What is compact bone
A
External dense layer of bone
14
Q
What is the medullary cavity
A
Hollow space in bone
15
Q
What are the 5 types of bone?
A
Long, short, sesamoid, flat, irregular
16
Q
Describe the general shape of long bones
A
Long, skinny shaft with knobs at either end
17
Q
Where are long bones found
A
Limbs
18
Q
What are the three regions of a long bone
A
Epiphyses, metaphyses, diaphysis
19
Q
What is an epiphysis
A
Extreme ends of long bones
20
Q
What is a metaphysis
A
Transitional zone between epiphyses and diaphyses of long bone
21
Q
What is a diaphysis
A
Shaft of long bone containing medullary cavity
22
Q
Give examples of long bones
A
Clavical, humerus, radius, ulna, metacarpals, phalanges
Femur, tibia, fibula, metatarsals, phalanges
23
Q
Describe the general shape of short bones
A
Small, square shaped, length=width
24
Q
Where are short bones found
A
Wrists and ankles
25
Give examples of short bones
Carpals, tarsals
26
Where are sesamoid bones found
Develop in tendons were friction is excessive
27
Give examples of sesamoid bones
Pisiform, patella
28
Describe the general shape of flat bones
Thin, broad, plate like structure
29
What is the general purpose of flat bones
Surround and protect body cavities
30
Give examples of flat bones
Skull cap (calvaria), scapulae, ribs, sternum, pelvic girdle
31
What are irregular bones
Bones which shape does not group with any other category
32
Give examples of irregular bones
Bones of face, vertebrae, sacrum
33
Flat bones make up the axial / appendicular / both skeleton?
Both
34
Irregular bones make up the axial / appendicular / both skeleton?
Axial
35
Long bones make up the axial / appendicular / both skeleton?
Appendicular
36
Sesamoid bones make up the axial / appendicular / both skeleton?
Appendicular (more friction in limbs)
37
Short bones make up the axial / appendicular / both skeleton?
Appendicular
38
Is bone dynamic or stagnant
Dynamic
39
What type of tissue is bone
Dense connective
40
What is the general makeup of bone tissue
Osseous cells suspended in a dense extracellular matrix
41
What are the two components of the extracellular matrix of bone tissue
Bone minerals, organic matrix
42
What percent of bone weight are bone minerals, organic matrix, and water
Minerals = 55%
Organic matrix = 30%
Water = 15%
43
What gives bone its characteristic hard structure
Bone minerals
44
Describe the composition of bone minerals
Mix of calcium salts (calcium, phosphate) combine to form hydroxyapatite, a mega crystal structure (hard)
45
What gives bone its flexibility
Organic matrix
46
Describe the composition of the organic matrix of bone tissue
Collagen fibers + ground substance + water forms the organic matrix
47
What property does the combination of bone minerals and organic matrix create
Tensile strength
48
Describe the transition between osteoprogenitor cells, osteoblasts, and osteocytes
Osteoprogenitor cells are capable of division and differentiate into osteoblasta which get trapped in the mineralized ECM and transition into osteocytes
49
What is the function of osteoprogentitor cells
Stem cells of bone; divide
50
What is the function of osteoblasts
Build up Bone; secrete organic bone matrix and begin calcification of bone matrix
51
What is the function of osteocytes
Mature bone cells that maintain daily metabolism, detect forces on bone
52
Describe the formation of osteoclasts
Monocytes (large cells from red bone marrow) fuse to form large multinucleated osteoclasts
53
What is the function of osteoclasts
Consume bone; when ruffled edge contacts bone, releases powerful lysosomal enzymes and acids
54
What is hydroxyapatite
Mineralized bone
55
What is the periosteum
External fibrous connective tissue layer that surrounds the compact bone
56
Where does the periosteum surround
All surfaces of bone / compact bone except articular surfaces
57
What is the endosteum
Connective tissue layer that lines the medullary cavity / spongey bone
58
Where is spongey bone found
At the ends of bone and lining the medullary cavity
59
How is spongey bone oriented
Along lines of stress / areas of tension and compression
60
Is spongey bone strong in bending or compression
Compression
61
Is compact bone strong in bending or compression
Bending
62
How is compact bone oriented
Longitudinally
63
Trabecular and cancellous bone are synonyms for
Spongey bone
64
Cortical and dense bone are synonyms for
Compact bone
65
What is a trabeculae a unit of
Spongy bone
66
What is an osteon a unit of
Compact bone
67
What are lamellae
Mineralized circular plates of bone matrix
68
Describe the concentric directional organization of concentric lamellae and its purpose
Alternating directions for concentric lamellae which gives more strength
69
What are interstitial lamellae
Broken down fragments of osteons in between osteons
70
What are concentric lamellae
Layers in an osteon
71
What are circumferential lamellae
Large plates that completely surround the external and internal circumferences of compact bone
72
Describe the pathway of nutrient vasculature
Nutrient artery enters at diaphysis and branches up and down the bone. Travels within the medullary capillary.
73
Describe the pathways of central canal capillaries
Travel up and down through center of osteons
74
Describe the pathway of periosteal vasculature
Runs superficially in periosteum
75
What are interosteonic canals and what is their purpose
Vascular communication between osteons and many sources of blood. Run horizontally into bone
76
What areas on bone receive sensory innervation? Somatic sensory innervation?
Sensory nerves reach all aspects of bone just by following vasculature. Periosteum is only area that receives somatic innervation
77
What is the purpose of sensory fibers within bone
Aid regulation of bone homeostasis and growth
78
Where is bone marrow found
In hollow portions on bone such as areas of excess spongy bone or within the medullary cavity of a long bone
79
What is the purpose of red bone marrow
Supports red and white blood cell formation and filters out out blood cells
80
What is the purpose of yellow bone marrow
Supports the vasculature within the medullary cavity and stores triglycerides
81
Where are osteocytes located (3 answers)
Between concentric lamellae, within compact bone, within spongy bone
82
What bone formation landmark is reached at by week 6 of embryonic development
Mesenchymal skeleton model is formed
83
What is mesenchyme
embryonic connective tissue, mostly mesoderm
84
What embryonic structure forms bone / ossifies
Mesenchyme ossifies
85
What are the two routes via which bone forms from mesenchyme
Intramembraneous and endochondral ossification
86
What is intramembraneous ossification
bone forms within mesenchyme
87
What bones form via intramembraneous ossification
most bones of the skull (facial bones and flat bones of calvaria) and the majority of the clavicle
88
What is endochondral ossification
Cartilage model forms within mesenchyme, bone forms within cartilage
89
What bones form via endochrondral ossification
base of skull (sphenoid, occipital, ethmoid) and most bones of body
90
Is mesenchyme vascular or avascular
Vascular
91
Describe the characteristics of the skeleton / bones at birth
Joints remain between flat bones of the skull that will later ossify
Bones forming through intramembraneous ossification are ossified
Diaphyses of long bones are ossified and have developed a medullary cavity
92
What is an increase in bone length called
Interstitial growth
93
Where does interstitial growth occur
At the epiphyseal plate, on the growth side
94
What is the epiphyseal plate
Growth plate
95
What is the epiphyseal plate made of
Hyaline cartilage
96
Do bones grow in length equally on both ends
No
97
What is an increase in bone width called
Appositional growth
98
Where does appositional growth occur
At the bones surface deep to the periosteum or at the medullary cavity superficial to the endosteum
99
What type of ossification is interstitial growth and appositional growth
Interstitial = endocondral
Appositional = different
100
What stimulates appositional growth
When muscle is used a lot, increased pulling on the surface of the bone
101
What is the mechanism of appositional growth
Superficial blood vessels get trapped and bone grows around it to form an osteon
102
What is bone remodeling
The process of replacing old bone with new bone
103
When does bone remodeling occur
Constantly
104
Why does bone remodeling occur
To maintain the strength and resilience of bone
105
What type of bone remodels faster, spongey or compact
Spongey
106
Name triggers for bone remodeling
Mechanical loading, endocrine signals, changes in mineral concentration in the blood
107
What is resportion
Osteoclasts remove and break down bone matrix and release minerals into the blood. Removal of minerals and collagen fibers from bone
108
What is deposition
Osteoblasts lay new bone, addition of minerals and collagen fibers to bone
109
How are minerals stored in bone released into the body
Resporption
110
What is the role of networks of osteocytes in bone remodeling
Sense strains on bone to decide where remodeling by other cells is necessary
111
What bone cells are involved in bone resorption? Deposition?
Osteoblasts = deposition
Osteoclasts = resorption
112
How does low gravity affect bone density
Decreases, less strain means less deposition
113
What are the main minerals stored in bone
Vitamin D, Calcium, Phosporous
114
What factors increase bone deposition
calcitonin, growth / sex hormones, mechanical loading (minerals needed)
115
What factors increase bone resorption
parathyroid hormone
116
What factors decrease bone resorption
calcitonin
117
Describe the effect of high serum calcium
Release of calcitonin, calcium deposited into bone, increased deposition, less absorption and more excretion of calcium through digestive and renal systems
118
Describe the effect of low serum calcium
Release of PTH from parathyroid gland, removal of calcium form bone to increase serum concentration, increased resorption, more absorption and reabsorption of calcium through digestive and renal systems
119
What hormone opposes calcitonin
PTH
120
What types of bone marrow is most active in kids
Red bone marrow
121
What is the function of red bone marrow in kids
Establish the immune system and populate the blood
122
How does bone marrow change with age
Red bone marrow becomes inactive and is replaced by yellow bone marrow
123
What is yellow bone marrow made of
Adipose tissue
124
In an adult, what bone contain red bone marrow and what bone contain yellow bone marrow
Red = axial skeleton and proximal humerus / femur
Yellow = rest
125
Name three processes which occur in bone with age and their effect on bone
1. demineralization = loss of bone mass
2. collagen production slows = brittleness
3. resorption > deposition = loss of bone mass
126
What is osteopenia
First stage loss of bone mass, increased risk for osteoporosis
127
What is osteoporosis
More severe loss of bone mass with enlarged spaces in bone
128
Why do older adults appear to shrink / hunch over
Collapse of vertebrae with bone breakdown
129
What are risk factors for low bone mass
age, decrease in sex hormones, family history, small build, inactivity
130
Which bone cells have which effects on improving low bone mass
stimulate osteoblasts = build bone
inhibit osteoclasts = stop bone breakdown
131
What are the three categories to classify fractures
type / shape, diplacement, penetration
132
What are the four types / shapes of bone fracture
oblique (angle), transverse (horizontal), communited (shattered), greenstick (incomplete)
133
What population gets greenstick fractures and why
Kids, bone has more flexibility
134
What are the three displacements of bone fracture
non-displaced (alligned), displaced (misalligned), impacted (pushed into one another)
135
What are the two penetrations of bone fracture
closed (within skin), open (sticking out of skin)
135
What is bone reduction
Setting a fracture, putting ends together to promote and set up for repair
136
What is closed reduction of bone
Manual manipulation with skin intact
137
What is open reduction of bone
Surgical intervention to reallign fracture
138
What are the steps to bone fracture repair
Formation of fracture hematoma, formation of fibrocartilaginous callus, formation of bony callus, remodeling of bone
139
What is a bone head
Proximal smooth end of a bone
140
What is a bone neck
narrowed portion distal to head
141
What is a bone condyle
rounded smooth projection(s), often distal
142
What is a bone facet
smooth, flat, articular surface
143
What is a bone fossa
shallow depression
144
What is a bone process
projection of varying length
145
What is a bone protuberance
blunt projection
146
What is a bone epicondyle
projection above or on condyle, muscles and ligaments that support a joint attach here
147
What is a bone tubercle
rounded projection
148
What is a bone tuberosity
roughened projection
149
What is a bone trochanter
prominent projection exclusive to femur
150
What is a bone line
elongated ridge
151
What is a bone crest
prominent ridge
152
What is a bone spine
sharp, narrow process
153
What is a bone foramen
opening or hole
154
What is a bone meatus
tube-like passage
155
What is a bone fissure
narrow irregular slit
156
What is a bone sulcus
groove
